Thorium chloride fused salt and preparation method thereof
By using Ar-HCl-CCl4 gas chlorinated ThO2 powder in molten salt medium, the problem of difficult to efficiently and safely prepare thorium chloride in traditional methods is solved, and the preparation of high-purity thorium chloride and environmentally friendly industrial production are achieved.
Patent Information
- Application Number
- CN202510439320.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-04
AI Technical Summary
The prior art is difficult to efficiently and safely prepare high-purity thorium chloride in a non-aqueous oxygen environment, and traditional methods are prone to introducing impurities and environmental pollution.
ThO2 powder was added to the molten salt medium, and the chlorination reaction was carried out through the Ar-HCl-CCl4 mixture gas to ensure that the thorium element does not come into contact with water and oxygen. The chlorination reaction was controlled using clear steps, and finally the Ar gas was passed into the reaction and cooled.
It achieves efficient chlorination and obtains high-purity thorium chloride, which reduces reaction time and energy consumption, reduces environmental pollution, and is suitable for industrial production.
Smart Images
Figure CN120247076A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of nuclear material preparation, and particularly to a thorium chloride molten salt and a preparation method thereof. Background Art
[0002] Thorium (Th), as an important strategic resource, has shown extremely broad application prospects in multiple fields such as nuclear energy, nuclear medicine, and new material development. Thorium chloride (ThCl4), as an important member of thorium compounds, is a key raw material for preparing high-purity thorium metal and its alloys. However, thorium has special chemical properties and shows extremely high sensitivity to water and oxygen, and is extremely prone to hydrolysis and oxidation reactions. This characteristic not only significantly increases the difficulty of the preparation process of high-purity thorium metal, but also seriously limits the efficiency and safety of its industrial production.
[0003] Traditional methods for preparing thorium chloride mainly use solid-gas reactions or direct chlorination methods. In these methods, the reaction often needs to be carried out under high-temperature conditions, and it is very difficult to completely avoid direct contact between thorium and moisture and oxygen in the air. This results in the purity of the final product being difficult to reach the ideal level, and at the same time brings environmental pollution problems and safety hazards. In addition, there is also a method of using AlCl3 to chlorinate thorium oxide in molten salt. The biggest disadvantage of this method is that it will introduce Al impurities. Therefore, there is an urgent need to develop a new method that can efficiently and safely prepare thorium chloride in a non-aqueous oxygen environment. Summary of the Invention
[0004] The purpose of the present invention is to provide a thorium chloride molten salt and a preparation method thereof. This method has the characteristics of efficient chlorination, high-purity products, environmental friendliness, and simple operation, significantly reducing the reaction time and energy consumption, while reducing environmental pollution. In addition, the steps of this method are clear and easy to achieve industrial scale-up production, providing high-quality raw material support for subsequent metallurgical treatment of thorium metal, and having significant industrial application potential.
[0005] To achieve the above purpose, the present invention provides a method for preparing a thorium chloride molten salt, including the following steps:
[0006] Step S1: Add ThO2 powder to the molten salt matrix, and stir well to make it evenly dispersed to obtain a uniformly mixed molten salt;
[0007] Step S2: Place the uniformly mixed molten salt in a crucible, and heat it in an electric resistance furnace at a heating rate of 5 °C / min to completely melt the molten salt and ensure that ThO2 is evenly distributed in the molten salt;
[0008] Step S3: Introduce an Ar-HCl-CCl4 mixed gas into the molten salt system, where HCl and CCl4 are used as chlorinating agents and Ar is used as a carrier gas;
[0009] Step S4: After introducing the Ar-HCl-CCl4 mixed gas, continue to introduce Ar-HCl gas into the molten salt system to promote the complete completion of the chlorination reaction of thorium.
[0010] Step S5: After introducing the Ar-HCl gas, continue to introduce Ar into the molten salt system.
[0011] Step S6: After the chlorination reaction is completed, stop gas supply and let the reaction system cool naturally to room temperature to obtain thorium chloride molten salt.
[0012] Preferably, in step S1, the molten salt matrix is any one of LiCl-KCl mixture, NaCl-KCl mixture, LiCl-KCl-CsCl mixture, LiCl-CaCl2 mixture, and KCl-MgCl2 mixture.
[0013] Among them, the mass ratios of the components of each mixture are as follows:
[0014] LiCl:KCl = 44.2:55.8; NaCl:KCl = 49.8:50.2; LiCl:KCl:CsCl = 29:24:47; LiCl:CaCl2 = 58:42; MgCl2:KCl = 68:32.
[0015] Preferably, in step S2, the heating temperature is 450 - 850 °C.
[0016] Preferably, in step S3, the purities of Ar, HCl, and CCl4 are 99.999%, 99.99%, and 99.5% respectively; the volume fractions of Ar, HCl, and CCl4 are 80 - 88%, 10%, and 2 - 10% respectively; the flow rate of the Ar-HCl-CCl4 mixed gas is 40 - 100 mL / min, and the gas supply time is 1 h.
[0017] Preferably, in step S4, the flow rate of the HCl gas is 40 - 100 mL / min, and the gas supply time is 30 minutes.
[0018] Preferably, in step S5, the flow rate of the Ar gas is 60 - 150 mL / min, and the gas supply time is 30 minutes.
[0019] The present invention also provides a thorium chloride molten salt prepared by the above preparation method of thorium chloride molten salt, and the content of the thorium chloride molten salt reaches more than 90%.
[0020] Therefore, by adopting the above-mentioned thorium chloride molten salt and preparation method, the present invention has the following beneficial technical effects:
[0021] (1) High-efficiency chlorination: By carrying out the chlorination reaction in a molten salt medium, the present invention significantly improves the chlorination efficiency. Compared with traditional methods, it greatly reduces the reaction time and energy consumption.
[0022] (2) High-purity product: The molten salt medium can effectively isolate water and oxygen, avoiding the oxidation and hydrolysis reactions of thorium elements, and thus successfully obtaining high-purity LiCl-KCl-ThCl4 molten salt. This provides high-quality raw materials for the subsequent metallurgical treatment of thorium metal, which is conducive to improving the quality of the final thorium metal product.
[0023] (3) Environmentally friendly: The entire preparation process is carried out in a closed system, effectively reducing the emission of harmful gases, conforming to the current development trend of green chemistry, and reducing environmental pollution.
[0024] (4) Simple operation: The method proposed by the present invention has clear steps, is easy to operate, and is easy to realize industrial scale-up production. This not only reduces production costs but also has good economic efficiency and practicality, providing a feasible technical solution for the large-scale production of thorium chloride. Description of the Drawings
[0025] Figure 1 It is a flow chart of a method for preparing a thorium chloride molten salt according to the present invention. Detailed Embodiments
[0026] The technical solutions of the present invention will be further described below with reference to the drawings and embodiments.
[0027] Unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meaning understood by those of ordinary skill in the field to which the present invention belongs.
[0028] Example 1
[0029] The preparation process of the thorium chloride molten salt is as Figure 1 shown.
[0030] Preparation of mixed salts: Weigh 44.2 g of LiCl, 55.8 g of KCl, and 10 g of ThO2 powder. After mixing them thoroughly, place them in a graphite crucible.
[0031] Heating to the reaction temperature: Put the graphite crucible containing the mixed molten salt into an electric resistance furnace, raise the temperature to 450 °C at a heating rate of 5 °C / min, and maintain a constant temperature.
[0032] Introduce the Ar-HCl-CCl4 mixed gas: Open valves 1, 2, 3, 4, 5, and 6. By adjusting the gas flow controller of valve 5, introduce a mixed gas of Ar (volume fraction 80%), HCl (volume fraction 10%), and CCl4 (volume fraction 10%) into the molten salt at a rate of 40 mL / min for 1 hour. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the acidic HCl gas introduced and generated during the process is absorbed repeatedly by the NaOH solution at two places.
[0033] Introduce the Ar-HCl gas: Close valves 1, 2, and 3, cut off the supply of CCl4, open valves 4, 5, and 6, and continue to introduce the Ar-HCl gas (HCl with volume fractions of Ar and HCl being 90% and 10% respectively, flow rate 40 mL / min) into the molten salt for 30 minutes to ensure the complete completion of the chlorination reaction. The excess HCl gas in the absorption process of the two NaOH solutions is absorbed.
[0034] Introduce Ar: Close valves 2 and 4, cut off the gas paths of HCl and CCl4, open valves 1, 3, 5, and 6, and continue to introduce Ar gas (flow rate 60 mL / min) into the molten salt for 30 minutes. Keep valve 6 open to ensure smooth gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0035] Product collection: Close valves 1, 2, 3, 4, and 5, open valve 6, stop gas introduction, let the reaction system cool naturally to room temperature, and the two NaOH solutions continue to absorb the residual HCl gas. After analysis and detection, finally about 113.5 g of the product is obtained, and the content of ThCl4 in the product reaches over 95%.
[0036] Example 2:
[0037] Preparation of the mixed salt: Weigh 88.4 g of LiCl, 111.6 g of KCl, and 20 g of ThO2 powder, mix them thoroughly, and place them in an alumina crucible.
[0038] Heat to the reaction temperature: Put the alumina crucible containing the mixed molten salt into an electric resistance furnace, raise the temperature to 800 °C at an appropriate heating rate, and maintain a constant temperature state.
[0039] Introduce the Ar-HCl-CCl4 mixed gas: Open valves 1, 2, 3, 4, 5, and 6. By adjusting the gas flow controller of valve 5, introduce the mixed gas of HCl and CCl4 (the volume fractions of Ar, HCl, and CCl4 are 85%, 10%, and 5% respectively) into the molten salt at a rate of 100 mL / min for 1 hour continuously. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the acidic HCl gas introduced and generated during the process is absorbed repeatedly by the NaOH solution at two places.
[0040] Introduce the Ar-HCl gas: Close valves 1, 2, and 3, cut off the supply of CCl4, open valves 4, 5, and 6, and continue to introduce the Ar-HCl gas (flow rate of 100 mL / min) (the volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. The excess HCl gas in the absorption process of the two NaOH solutions is absorbed.
[0041] Introduce Ar: Close valves 2 and 4, cut off the gas paths of HCl and CCl4, open valves 1, 3, 5, and 6, and continue to introduce Ar gas (flow rate of 150 mL / min) into the molten salt for 30 minutes continuously. Keep valve 6 open to ensure the smoothness of the gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0042] Product collection: Close valves 1, 2, 3, 4, and 5, open valve 6, stop gas introduction, let the reaction system cool naturally to room temperature, and the two NaOH solutions continue to absorb the residual HCl gas. After analysis and detection, finally, about 228.3 g of product is obtained, and the content of ThCl4 in the product reaches more than 95%.
[0043] Example 3
[0044] Preparation of mixed salt: Weigh 49.8 g of NaCl, 50.2 g of KCl, and 10 g of ThO2 powder, mix them thoroughly, and place them in a graphite crucible.
[0045] Heat to the reaction temperature: Put the graphite crucible containing the mixed molten salt into an electric resistance furnace, raise the temperature to 700 °C at an appropriate heating rate, and maintain a constant temperature state.
[0046] Introduce the Ar-HCl-CCl4 mixed gas: The valve switch is the same as in the example. By adjusting the gas flow controller, introduce a mixed gas of HCl (volume fraction 10%) and CCl4 (Ar, HCl, and CCl4 have volume fractions of 87%, 10%, and 3% respectively) into the molten salt at a rate of 50 mL / min for 1 hour. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the HCl acidic gas introduced and generated during the process is repeatedly absorbed by the NaOH solution at two places.
[0047] Introduce the Ar-HCl gas: The valve switch is the same as in the example. Close the supply of CCl4 and continue to introduce the Ar-HCl gas (flow rate 50 mL / min) (Ar and HCl have volume fractions of 90% and 10% respectively) into the molten salt for 30 minutes to ensure that the chlorination reaction is completely completed. The excess HCl gas in the absorption process of the two NaOH solutions is absorbed.
[0048] Introduce high-purity Ar: The valve switch is the same as in the example. Close the HCl gas path and continue to introduce pure Ar gas (flow rate 80 mL / min) into the molten salt for 30 minutes. Keep valve 6 open to ensure smooth gas flow, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0049] Product collection: The valve switch is the same as in the example. Stop introducing the gas and let the reaction system cool naturally to room temperature. The two NaOH solutions continue to absorb the residual HCl gas. After analysis and detection, finally, about 113.2 g of the product is obtained, and the content of ThCl4 in the product reaches more than 93%.
[0050] Example 4
[0051] Prepare the mixed salt: Weigh 99.6 g of NaCl, 100.4 g of KCl, and 20 g of ThO2 powder. After mixing them thoroughly, place them in a graphite crucible.
[0052] Heat to the reaction temperature: Put the graphite crucible containing the mixed molten salt into the resistance furnace and raise the temperature to 850 °C at an appropriate heating rate and keep it at a constant temperature.
[0053] Introduce the Ar-HCl-CCl4 mixed gas: The valve switch is the same as in the example. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl, and CCl4 (Ar, HCl, and CCl4 have volume fractions of 82%, 10%, and 8% respectively) into the molten salt at a rate of 80 mL / min for 1 hour. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the HCl acidic gas introduced and generated during the process is repeatedly absorbed by the NaOH solution at two places.
[0054] Introduce Ar-HCl gas: The valve switches are the same as in the examples. Close the supply of CCl4, and continue to introduce Ar-HCl gas (flow rate: 80 mL / min) (volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. Excess HCl gas in the two NaOH solution absorption processes is absorbed.
[0055] Introduce Ar: The valve switches are the same as in the examples. Close the HCl gas path, and continue to introduce Ar gas (flow rate: 130 mL / min) into the molten salt for 30 minutes continuously. Keep valve No. 6 open to ensure the smooth gas path, and at the same time, the residual HCl gas is absorbed by the NaOH solution.
[0056] Product collection: The valve switches are the same as in the examples. Stop introducing gas, and let the reaction system cool naturally to room temperature. The two NaOH solution absorption processes continue to absorb the residual HCl gas. After analysis and detection, finally about 231.4 g of the product is obtained, and the content of ThCl4 in the product reaches more than 94%.
[0057] Example 5
[0058] Preparation of mixed salt: Weigh 29 g, 24 g, and 47 g of LiCl, KCl, and CsCl respectively. Then weigh 10 g of ThO2 powder, mix them evenly, and place them in an alumina crucible.
[0059] Heat to the reaction temperature: Put the alumina crucible containing the mixed molten salt into an electric resistance furnace, and increase the temperature to 500 °C at an appropriate heating rate and keep it at a constant temperature.
[0060] Introduce Ar-HCl-CCl4 mixed gas: The valve switches are the same as in the examples. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl, and CCl4 (volume fractions of Ar, HCl, and CCl4 are 88%, 10%, and 2% respectively) into the molten salt at a rate of 40 mL / min for 1 hour continuously. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve No. 6 open, and the HCl acidic gas introduced and generated during the process is repeatedly absorbed by the two NaOH solution absorption processes.
[0061] Introduce Ar-HCl gas: The valve switches are the same as in the examples. Close the supply of CCl4, and continue to introduce Ar-HCl gas (flow rate: 40 mL / min) (volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. Excess HCl gas in the two NaOH solution absorption processes is absorbed.
[0062] Introduce Ar: The valve switch is the same as in the embodiment. Close the HCl gas path, and continue to introduce Ar gas (flow rate: 60 mL / min) into the molten salt for 30 minutes continuously. Keep valve No. 6 open to ensure smooth gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0063] Product collection: The valve switch is the same as in the embodiment. Stop introducing gas, and let the reaction system cool down to room temperature naturally. The two NaOH solutions continue to absorb the residual HCl gas. After analysis and detection, finally about 116.6 g of product is obtained, and the content of ThCl4 in the product reaches more than 95%.
[0064] Example 6
[0065] Preparation of mixed salt: Weigh 58 g, 48 g, and 94 g of LiCl, KCl, and CsCl respectively. Then weigh 20 g of ThO2 powder, mix them evenly, and place them in an alumina crucible.
[0066] Heat to reaction temperature: Put the alumina crucible containing the mixed molten salt into an electric resistance furnace, and increase the temperature to 850 °C at an appropriate heating rate and keep it at a constant temperature.
[0067] Introduce Ar-HCl-CCl4 mixed gas: The valve switch is the same as in the embodiment. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl, and CCl4 (volume fractions of Ar, HCl, and CCl4 are 80%, 10%, and 10% respectively) into the molten salt at a rate of 100 mL / min for 1 hour continuously. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve No. 6 open, and the HCl acidic gas introduced and generated during the process is repeatedly absorbed by the two NaOH solutions.
[0068] Introduce Ar-HCl gas: The valve switch is the same as in the embodiment. Close the supply of CCl4, and continue to introduce Ar-HCl gas (flow rate: 100 mL / min) (volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. The two NaOH solutions absorb the excess HCl gas in the process.
[0069] Introduce Ar: The valve switch is the same as in the embodiment. Close the HCl gas path, and continue to introduce Ar gas (flow rate: 150 mL / min) into the molten salt for 30 minutes continuously. Keep valve No. 6 open to ensure smooth gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0070] Product collection: The valve switch is the same as in the examples. Stop introducing gas and let the reaction system cool naturally to room temperature. The two NaOH solutions continue to absorb the residual HCl gas. After analysis and testing, finally about 232.2 of the product is obtained, and the content of ThCl4 in the product reaches more than 94%.
[0071] Example 7
[0072] Preparation of mixed salt: Weigh 58 g of LiCl and 42 g of CaCl2 respectively. Then weigh 10 g of ThO2 powder, mix them thoroughly and place them in a graphite crucible.
[0073] Heating to reaction temperature: Put the graphite crucible containing the mixed molten salt into an electric resistance furnace, raise the temperature to 500 °C at an appropriate heating rate and keep it at a constant temperature.
[0074] Introducing Ar-HCl-CCl4 mixed gas: The valve switch is the same as in the examples. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl and CCl4 (the volume fractions of Ar, HCl and CCl4 are 84%, 10% and 6% respectively) into the molten salt at a rate of 40 mL / min for 1 hour. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the HCl acidic gas introduced and generated during the process is repeatedly absorbed by the two NaOH solutions.
[0075] Introducing Ar-HCl gas: The valve switch is the same as in the examples. Close the supply of CCl4 and continue to introduce Ar-HCl gas (flow rate of 40 mL / min) (the volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes to ensure that the chlorination reaction is completed thoroughly. The two NaOH solutions absorb the excess HCl gas in the process.
[0076] Introducing Ar: The valve switch is the same as in the examples. Close the HCl gas path and continue to introduce Ar gas (flow rate of 60 mL / min) into the molten salt for 30 minutes. Keep valve 6 open to ensure smooth gas path, and at the same time the NaOH solution absorbs the residual HCl gas.
[0077] Product collection: The valve switch is the same as in the examples. Stop introducing gas and let the reaction system cool naturally to room temperature. The two NaOH solutions continue to absorb the residual HCl gas. After analysis and testing, finally about 113.1 g of the product is obtained, and the content of ThCl4 in the product reaches more than 91.5%.
[0078] Example 8
[0079] Mixed salt preparation: Weigh 580 g of LiCl and 420 g of CaCl2 respectively. Then weigh 100 g of ThO2 powder, mix them thoroughly, and place them in a graphite crucible.
[0080] Heating to reaction temperature: Put the graphite crucible containing the mixed molten salt into an electric resistance furnace, raise the temperature to 500 °C at an appropriate heating rate, and maintain a constant temperature.
[0081] Introducing Ar-HCl-CCl4 mixed gas: The valve switches are the same as in the example. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl, and CCl4 (the volume fractions of Ar, HCl, and CCl4 are 80%, 10%, and 10% respectively) into the molten salt at a rate of 100 mL / min for 1 hour continuously. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the HCl acidic gas introduced and generated during the process is absorbed repeatedly by the NaOH solution at two places.
[0082] Introducing Ar-HCl gas: The valve switches are the same as in the example. Close the supply of CCl4, and continue to introduce Ar-HCl gas (flow rate of 100 mL / min) (the volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. The excess HCl gas in the absorption process of the two NaOH solutions is absorbed.
[0083] Introducing Ar: The valve switches are the same as in the example. Close the HCl gas path, and continue to introduce Ar gas (flow rate of 150 mL / min) into the molten salt for 30 minutes continuously. Keep valve 6 open to ensure smooth gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0084] Product collection: The valve switches are the same as in the example. Stop introducing gas, let the reaction system cool naturally to room temperature, and the two NaOH solutions continue to absorb the residual HCl gas. After analysis and detection, finally obtain about 1161 g of product, and the content of ThCl4 in the product reaches more than 94%.
[0085] Example 9
[0086] Mixed salt preparation: Weigh 68 g of MgCl2 and 32 g of KCl. Then weigh 10 g of ThO2 powder, mix them thoroughly, and place them in a graphite crucible.
[0087] Heating to reaction temperature: Put the graphite crucible containing the mixed molten salt into an electric resistance furnace, raise the temperature to 500 °C at an appropriate heating rate, and maintain a constant temperature.
[0088] Introduce the Ar-HCl-CCl4 mixed gas: The valve switches are the same as in the examples. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl, and CCl4 (with volume fractions of Ar, HCl, and CCl4 being 87%, 10%, and 3% respectively) into the molten salt at a rate of 40 mL / min for 1 hour continuously. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the HCl acidic gas introduced and generated during the process is absorbed repeatedly by the NaOH solutions at two places.
[0089] Introduce the Ar-HCl gas: The valve switches are the same as in the examples. Close the supply of CCl4 and continue to introduce the Ar-HCl gas (flow rate is 40 mL / min) (with volume fractions of Ar and HCl being 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. The excess HCl gas in the absorption process of the two NaOH solutions is absorbed.
[0090] Introduce Ar: The valve switches are the same as in the examples. Close the HCl gas path and continue to introduce Ar gas (flow rate is 60 mL / min) into the molten salt for 30 minutes continuously. Keep valve 6 open to ensure the smoothness of the gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0091] Product collection: The valve switches are the same as in the examples. Stop introducing the gas and let the reaction system cool naturally to room temperature. The two NaOH solutions continue to absorb the residual HCl gas. After analysis and detection, finally obtain about 113.4 g of the product, and the content of ThCl4 in the product reaches more than 92%.
[0092] Example ten
[0093] Preparation of the mixed salt: Weigh 136 g of MgCl2 and 64 g of KCl. Then weigh 20 g of ThO2 powder, mix them thoroughly, and place them in an alumina crucible.
[0094] Heat to the reaction temperature: Put the graphite crucible containing the mixed molten salt into the resistance furnace, raise the temperature to 800 °C at an appropriate heating rate, and maintain a constant temperature state.
[0095] Introduce the Ar-HCl-CCl4 mixed gas: The valve switches are the same as in the examples. By adjusting the gas flow controller, introduce a mixed gas of Ar, HCl, and CCl4 (with volume fractions of Ar, HCl, and CCl4 being 82%, 10%, and 8% respectively) into the molten salt at a rate of 100 mL / min for 1 hour continuously. During the gas introduction process, ensure that the gas is evenly dispersed in the molten salt. Keep valve 6 open, and the HCl acidic gas introduced and generated during the process is absorbed repeatedly by the NaOH solutions at two places.
[0096] Introduce Ar-HCl gas: The valve switches are the same as in the examples. Close the supply of CCl4, and continue to introduce Ar-HCl gas (flow rate: 100 mL / min) (the volume fractions of Ar and HCl are 90% and 10% respectively) into the molten salt for 30 minutes continuously to ensure the complete completion of the chlorination reaction. Two NaOH solution absorption processes are used to absorb the excess HCl gas.
[0097] Introduce Ar: The valve switches are the same as in the examples. Close the HCl gas path, and continue to introduce Ar gas (flow rate: 150 mL / min) into the molten salt for 30 minutes continuously. Keep valve No. 6 open to ensure smooth gas path, and at the same time, the NaOH solution absorbs the residual HCl gas.
[0098] Product collection: The valve switches are the same as in the examples. Stop introducing gas, and let the reaction system cool naturally to room temperature. The two NaOH solution absorption processes continue to absorb the residual HCl gas. After analysis and detection, finally about 226.7 g of product is obtained, and the content of ThCl4 in the product reaches over 94%.
[0099] It should be noted that the content not elaborated in detail in the present invention is prior art and well-known to those skilled in the art.
[0100] Therefore, the present invention adopts the above-mentioned molten salt of thorium chloride and its preparation method. This method has the characteristics of high-efficiency chlorination, high-purity products, environmental friendliness and simple operation, significantly reducing the reaction time and energy consumption, and at the same time reducing the environmental pollution. In addition, the steps of this method are clear and easy to realize industrial scale-up production, providing high-quality raw material support for the subsequent metallurgical treatment of thorium metal, and having significant industrial application potential.
[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A preparation method of thorium chloride molten salt, characterized in that, It includes the following steps: Step S1: Add ThO2 powder into the molten salt matrix, stir well to make it evenly dispersed, and obtain a uniformly mixed molten salt; Step S2: Place the uniformly mixed molten salt in a crucible, heat it in an electric resistance furnace at a heating rate of 5 °C / min to completely melt the molten salt and ensure that ThO2 is evenly distributed in the molten salt; Step S3: Pass an Ar-HCl-CCl4 mixed gas into the molten salt system, where HCl and CCl4 are used as chlorinating agents and Ar is used as a carrier gas; Step S4: After the Ar-HCl-CCl4 mixed gas is introduced, continue to pass an Ar-HCl gas into the molten salt system to promote the complete completion of the chlorination reaction of thorium; Step S5: After the Ar-HCl gas is introduced, continue to pass Ar into the molten salt system; Step S6: After the chlorination reaction is completed, stop ventilation and let the reaction system cool naturally to room temperature to obtain a thorium chloride molten salt.
2. The preparation method of thorium chloride molten salt according to claim 1, characterized in that, In Step S1, the molten salt matrix is any one of a LiCl-KCl mixture, a NaCl-KCl mixture, a LiCl-KCl-CsCl mixture, a LiCl-CaCl2 mixture, and a KCl-MgCl2 mixture; Among them, the mass ratios of the components of each mixture are as follows: LiCl:KCl = 44.2:55.8; NaCl:KCl = 49.8:50.2; LiCl:KCl:CsCl = 29:24:47; LiCl:CaCl2 = 58:42; MgCl2:KCl = 68:
32.
3. The preparation method of thorium chloride molten salt according to claim 1, characterized in that, In Step S2, the heating temperature is 450 - 850 °C.
4. The preparation method of thorium chloride molten salt according to claim 1, characterized in that, In Step S3, the purities of Ar, HCl, and CCl4 are 99.999%, 99.99%, and 99.5% respectively; the volume fractions of Ar, HCl, and CCl4 are 80 - 88%, 10%, and 2 - 10% respectively; the flow rate of the Ar-HCl-CCl4 mixed gas is 40 - 100 mL / min, and the ventilation time is 1 h.
5. A method for preparing thorium chloride molten salt according to claim 1, characterized in that, In Step S4, the flow rate of the HCl gas is 40 - 100 mL / min, and the introduction time is 30 minutes.
6. The preparation method of thorium chloride molten salt according to claim 1, characterized in that, In Step S5, the flow rate of the Ar gas is 60 - 150 mL / min, and the introduction time is 30 minutes.
7. A thorium chloride molten salt prepared by the preparation method of the thorium chloride molten salt according to any one of claims 1-6, characterized in that, The content of the thorium chloride molten salt reaches more than 90%.